


to keep me right on

by harperuth



Series: i met you in the summer [8]
Category: The Transformers (IDW Generation One), Transformers - All Media Types, Transformers: Prime
Genre: Dubious Consent, Hate Sex, Knotting, M/M, Primacy AU, implied mechpreg, one joke about necrophilia sorry, welcome to primacy tarn he's terrible!!
Language: English
Status: Completed
Published: 2020-08-09
Updated: 2020-08-09
Packaged: 2021-03-05 21:41:10
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,370
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25812232
Author URL: https://archiveofourown.org/users/harperuth/pseuds/harperuth
Summary: Deathsaurus made sure he had a good enough grip before shoving Tarn up and flipping him around, throwing his weight on Tarn’s back. Tarn growled, but his hips pushed back into him. “Frag off.”“Nah.” Deathsaurus set up a slow pace, grinding his pressurizing spike against Tarn’s aft. “I’ll fuck you, though.”
Relationships: Deathsaurus/Tarn (Transformers)
Series: i met you in the summer [8]
Series URL: https://archiveofourown.org/series/1828810
Comments: 11
Kudos: 78





	to keep me right on

**Author's Note:**

> hello this ended up being in the primacy verse and i don't!!! know how!!!! but primacy tarn is here and he's TERRIBLE. tarn/deathsaurus isn't an endgame in primacy, but it sure is fun along the way!!! anyway, i guess this is a weird setup to my new primacy fixation, we'll see when that comes out lol
> 
> for the prompt 'knotting' with tarn/deathsaurus
> 
> title is from 'crazy bitch' by buckcherry bc. well. [gestures]

They always ended up here. Deathsaurus felt a trickle of amusement at Tarn’s easily read frustration where he panted against Deathsaurus’s chest. His exvents fogged the metal of his chest.

“You done?” Deathsaurus rumbled, just for the satisfaction of knowing what it did to Tarn.

“Frag you,” Tarn snarled.

“I mean, you tried,” Deathsaurus said, shifting and feeling transfluid drip from him. His frame still sung with charge, not managing even a minor overload from Tarn’s rutting. Tarn tensed, but didn’t peel himself away. Deathsaurus could feel the answering charge still in his frame.

They always ended up here.

Deathsaurus sighed and brought his hands up to dig into Tarn’s treads. He wasn’t nice about it. His claws sunk into soft rubber until they almost pierced, but Tarn did nothing more than hiss and press into it. He didn’t voice his thoughts. Hadn’t gone well the last time.

_Why do you do things you don’t like?_

_Why won’t you shut up and let me fuck you? We both know that’s what you want._

Whatever, Deathsaurus had finally decided. Getting them both to where they needed to be was worth a few kliks of frustration and cleaning transfluid out of his valve. Shit stupid to get sparked up by accident, and especially by _Tarn_. The sparkling would cry wrong and melt his spark. While still forging. No thanks.

Deathsaurus made sure he had a good enough grip before shoving Tarn up and flipping him around, throwing his weight on Tarn’s back. Tarn growled, but his hips pushed back into him. “Frag off.”

“Nah.” Deathsaurus set up a slow pace, grinding his pressurizing spike against Tarn’s aft. “I’ll fuck you, though.”

They always ended up here.

Tarn’s vents spilled steam, but his fans also kicked up a notch and his valve panel slid back. Deathsaurus laughed, just a little meanly, next to his audial. “Yeah.”

Tarn was stubbornly silent. Whatever. Deathsaurus didn’t take the obvious invitation, continuing to rut against Tarn’s aft instead. Maybe next time he’d let Tarn get really tired out, let him try and fuck him through more than one overload, and then he’d fuck Tarn’s aft port. The thought was enough to send a zing of charge through his system. Yeah. He’d try it.

Tarn huffed a frustrated sound and tilted his hips back. Deathsaurus grinned and licked his audial. “You want something?”

Tarn huffed again. Deathsaurus bit into the ridge of dermametal behind his audial and thrust his hips forward. Hard. Tarn let out a grunt, then hissed, “Frag me.”

“What was that?” Deathsaurus rolled his hips again, letting the very base of his spike press on Tarn’s mesh. He could feel Tarn’s denta grinding from where his mouth was pressed against his audial. 

“Frag. Me.” Tarn grit out.

“Since you asked so nicely,” Deathsaurus said, and pulled back enough to line up and thrust his spike in in one push. Tarn howled beneath him. Deathsaurus ignored him, sitting back until he was upright and pulling Tarn’s hips with him.

Tarn’s valve squeezed a counterpoint around the pulsing of energon in his spike, and Deathsaurus arranged him just the right way to ensure that Tarn had no leverage, hips pulled back into his lap, knees not quite reaching the berth, valve full and aching. “Well, you want to be fucked so bad, do something about it.”

Deathsaurus could get off like this. Probably would. Tarn...might.

He listened to Tarn’s pedes scrabble at the berth as he tried to prop himself up, but his spread thighs rendered his knee joints all but useless. Top heavy son of a bitch. Deathsaurus grinned as his spike was squeezed over and over again while Tarn struggled. He waited.

Tarn finally stilled, steam pouring from every one of his vents. Deathsaurus ran a hand down his back, feeling the stuttering start and stop of his t-cog trying to engage. “Heh. You done?”

“I hope you fall in a smelter,” Tarn growled. Deathsaurus liked that. He liked that a lot.

“Yeah, okay.” He dug his fingers in Tarn’s tread’s once more, using the other hand to tilt Tarn’s hips just the way he wanted them.

He pulled back.

Thrust in hard.

The punched out groan from Tarn’s vocalizer sent charge bubbling through his circuits, a gentle wave compared to the heat from his spike being squeezed once again. Deathsaurus didn’t pause for long.

Tarn was always quiet when they started, but he gradually devolved into whining huffs and eventual moans. Deathsaurus made it his mission to pound every last little sound he could out of Tarn, if for nothing but the satisfaction of knowing he had. He twisted his hips on a particularly vicious thrust, getting just the right angle to get the very last nanomechanometer of his spike in.

His knotting protocols jumped to the front of his processing queue.

Yeah.

Okay.

Deathsaurus leaned more on Tarn and ground his hips against him, not pulling back. He engaged the protocols. He couldn’t remember if he’d told Tarn about this particular feature.

Oh well.

Deathsaurus wormed his fingers into the top of Tarn’s pelvic plate, getting a good grip and making sure he stayed close. He circled his hips in a tight grind as his protocols engaged, his knot expanding. “Surprise.”

Tarn managed an entire _moan_. 

Deathsaurus groaned at the sound and the way Tarn tightened around him, squeezing his knot. Deathsaurus dug his fingers harder into Tarn’s treads, grinding almost desperately. 

“Come on. Come on.” He didn’t realize he was muttering until Tarn groaned beneath him.

“Shut up,” He hissed. Deathsaurus ignored him. His knot reached full expansion, and for one crystalline moment he hung in the balance. Tarn squirmed underneath him, valve squeezing his knot almost to the point of pain. Charge burst through his wires like magnesium in water.

It abruptly rushed to his array and transfluid reserves as he started the long process of overload. 

It wasn’t like the normal rush of fluid and flashfire of charge. No, this was long, slow pulses throughout his array. Transfluid pushed through his channel slowly enough that he could feel it spilling its way out and into Tarn.

He’d had a partner once that had managed to fuck him through knotting their hand. That had been pretty incredible. Too bad Tarn sucked at fucking. He cobbled together his processor out of the protocols and memory files long enough to say, “If you so much as think about opening your forge seal right now, I will end your life right here. On my spike.”

“You into corpse fragging?” Tarn bit back, speech slurred. Oh. He’d managed to overload. Good for him.

“Shit happens,” Deathsaurus grunted back as another pulse of transfluid spilled from the end of his spike.

“Slag,” Tarn swore, and Deathsaurus felt him clench around him weakly. “Stop blowing your load right across my seal then.”

“Deal with it,” Deathsaurus said, protocols caught up in the fantasy of using his knot _right_ , of _breeding_. Shut the fuck up, he thought at them, pushing them along as quick as he could. He’d gotten his, Tarn had gotten something twice over, and he wanted to leave.

Afterglow, thy name sure as fuck weren’t Tarn.

“You almost done in there?” Tarn jerked his hips, pulling at the tie. They both hissed.

“Gimme a klik,” Deathsaurus grit out, “Fuck’s sake.”

“Fuck’s been sated,” Tarn spat back, overload relaxation already receding from his frame and the stick going right back up his aft. Probably why he fucked so poorly. Hard to move your hips with a rod up there. “Get out.”

“I’m _trying_ ,” Deathsaurus said, prodding at his protocols again. He found an errant line of code and triggered it. His knot finally went down, but his spike was still pressurized, steadily drooling transfluid. A gob oozed over Tarn’s aft when he finally pulled out. Deathsaurus snickered.

“What?” Tarn closed his panel almost immediately. Deathsaurus didn’t bother with answering him. They were done here. He didn’t spend much longer lingering, smacking Tarn’s aft and spattering his transfluid before seeing himself out of the apartment.

And if his spike left a trail through the whole place well—

Just something to remember him by until next time.

**Author's Note:**

> i'm taking summer heat prompts on twitter [@robopunkcfb](https://twitter.com/robopunkcfb)


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